This invention relates to two-part electrical connectors and in particular to connectors of the cable mounted type. Connectors of the type typically used in, for example, data transmission cabling systems, such as twin-axial plugs, conventionally have a one piece metallic body which is neither earthed nor insulated. Such twin-axial plugs are often used in computer cabling systems and are thus likely to be accessible to office personnel with little technical knowledge. Furthermore, such connectors have means for locking the two parts of the connector together with the result that tension on the cable tends to result in damage within the connector rather than separation of the two connector parts. Such damage may involve breaking of electrical connections or fracture of plastics components. This may in turn result in the accidental connection of the metallic outer casing to a high voltage potential by way of one of the conductors in the cable. Such accidental connection can, of course, lead to injury of persons working on equipment connected by means of such cable mounted connectors or possible damage to the equipment itself.